Recovering dipole sources from scalp-recorded event-related-potentials using component analysis: principal component analysis and independent component analysis.

Principal component analysis (PCA) and independent component analysis (ICA) were examined in their ability to recover dipole sources from simulated data. Datasets of EEG segments were generated that contained cortical sources that were temporally overlapping or non-overlapping, and dipole sources with varying degree of spatial orthogonality. For temporal overlapping sources, both PCA and ICA resulted in components that required multiple-source equivalent current dipole models. The spatially overlapping sources affected the PCA method more than ICA, resulting in single PCA components in which all non-orthogonal sources were represented. For both PCA and ICA, dipole models with fixed-location dipoles successfully accounted for most of the variance in the component weights, even when the spatial or temporal overlap of the generating sources required multiple-dipole models.     

Intensive versus standard blood glucose awareness training (BGAT) with insulin-dependent diabetes: mechanisms and ancillary effects

Insulin-dependent diabetes mellitus (IDDM) patients make critical daily self-care decisions on the basis of what they estimate their blood glucose (BG) levels to be. This study: a) replicated efficacy of Standard Blood Glucose Awareness Training (BGAT), b) evaluated the relative efficacy of an Intensive Blood Glucose Awareness Training (BGAT) to enhance patient accuracy of BG estimation, and c) evaluated the mechanisms and ancillary effects of BGAT. Thirty-nine subjects were randomly assigned to one of three groups. Compared with Control, both Standard and Intensive BGAT improved accuracy (p less than 0.001). Intensive BGAT post-treatment accuracy relative to Standard BGAT did not reach statistical significance (p = 0.177). Greater improvement in accuracy was associated with poorer pretreatment accuracy. Only Intensive BGAT improved metabolic control (glycosylated hemoglobin), and this improvement was associated with poorer pretreatment control. The effects of BGAT were highly specific, affecting only accuracy and metabolic control, and not affecting fear of hypoglycemia, diabetes knowledge, of frequency of blood glucose monitoring.     

Chemotherapy of advanced breast cancer: outcome and prognostic factors.

The outcome for 758 consecutive patients who had received one or more chemotherapy regimens for recurrent or metastatic breast cancer is presented. The response rate following first line treatment was 34%. Median duration of response was 7.8 months, median time to progression was 3.7 months and median survival was 7.9 months. The only factor predicting for response, of factors recorded at presentation and at initiation of chemotherapy, was the use of anthracycline based regimens, though this may reflect the patient selection policy. Initial disease free interval, presence of liver metastases and use of anthracyclines were significantly related to time to progression. Several factors related to survival following first chemotherapy, but anthracycline usage showed only a very weak correlation. One third of patients (249/758) received two or more chemotherapy regimens. The response rate (16%) and median time to progression (2.3 months) were significantly worse than for first line treatment. The outcome after third line chemotherapy was very similar to that observed following second line treatment. Achievement of an objective response with first line chemotherapy predicted for second response, but with insufficient power to be of use in selecting patients for subsequent chemotherapy. Time to progression following first line chemotherapy did not influence that after second line treatment.     

Results of a nationwide prospective audit of stoma complications within 3 weeks of surgery

OBJECTIVE: Actuarial analysis of stoma complications (problematic stomas) is lacking. The objectives of this audit were: to identify the incidence of stoma complications within the UK; to highlight any dissimilarity of incidence from centre to centre; to ascertain if the height of the stoma (distance of stoma lumen from the skin) at the time of fashioning is a predisposing factor to problems; and finally to initiate much needed research. METHOD: Commencing 1st January 2005, stoma care services nationwide (256) were invited to audit prospectively their next 50 enteric stomas or for a period of 1 year which ever came first. The definition of a problematic stoma being one, which needed one or more accessories to keep the patient clean and dry for a minimum period of 24 h. The incident is to have happened within 3 weeks of surgery. Factors taken into account were: type of stoma, height of stoma within 48 h of surgery; emergency or elective procedure, problem identified, BMI, gender and underlying diagnosis of the patient. The identities of the participating centres are confidential. RESULTS: Of the 256 hospital-based stoma care services within the UK, 93 (36%) participated. A total of 3970 stomas were recorded, of which 1329 (34%) were identified as problematic. Sixty-two centres reported 45-50 stomas with a range of complications 6-96%. The loop ileostomy was found to be the stoma which causes most problems. A stoma of <10 mm is a predisposing factor to complications and problems are more likely to occur following an emergency procedure. More men than women have stomas formed, but have significantly fewer problems and there is no significant difference between underlying diagnoses. CONCLUSION: The stoma height, stoma type and gender of the patient are significant risk factors identified in this audit. The BMI of patient did not affect the outcome. Patients undergoing an emergency procedure are more likely to have a problematic stoma. The significant variation of complications from centre to centre indicates surgical technique as being the key factor in stoma formation and subsequent quality of life for the patient.     

Leukaemia Inhibitory Factor or Related Factors Promote the Differentiation of Neuronal and Astrocytic Precursors within the Developing Murine Spinal Cord

Previously we have shown that leukaemia inhibitory factor (LIF) potentiates the development of murine spinal cord neurons in vitro , suggesting that it, or related factors, may play an important regulatory role in neuronal development. We have further investigated this role and show here that the generation of neurons in cultures of embryonic day 10 spinal cord cells is inhibited by antibodies to the β subunit of the LIF receptor. Since there are more undifferentiated precursors in antibody-treated cultures than in control and LIF-treated cultures, it is concluded that the primary action of LIF, or related molecules, is to promote neuronal differentiation, not precursor survival. In addition, the failure of LIF to support neuronal survival in the period immediately following differentiation suggests that the increased numbers of neurons generated with LIF are not attributable to its neurotrophic action. By selecting neuronal precursors on the basis of their inability to express class I major histocompatibility complex molecules, it was shown that LIF acted directly upon these cells and not via an intermediary cell. LIF also appears to be involved in regulating the differentiation of astrocytes, since it increases the number of glial fibrillary protein (GFAP)-positive cells present in the cultures and since the spontaneous production of GFAP-positive cells is blocked by antibodies to the LIF β receptor. These findings suggest that LIF or related factors promote the differentiation of neural precursors in the spinal cord, but that they are not involved in preferentially promoting precursors down a specific differentiation pathway.     

An alternative technique for laparoscopic cholangiography

The current methods utilized for laparoscopic cholangiography involve cystic duct cannulation and present practical difficulties and potential hazards. An alternative method for intraoperative cholangiography is described which is easy, quick, and safe. The Kumar clamp (a gift from Sabi Kumar, M.D.) is placed across the infundibulum. A 23-gauge sclerotherapy needle is introduced through a side port in the clamp and directed into the infundibulum. The cholangiogram is obtained prior to any dissection in the triangle of Calot, thereby avoiding iatrogenic common bile duct injuries due to misidentification of the cystic duct or anomalous anatomy. To date no pathology has been missed and no complications have resulted from this technique.